Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
  • B32B5/22—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed
  • B32B5/24—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer
  • B32B5/26—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer another layer next to it also being fibrous or filamentary
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/04—Reinforcing macromolecular compounds with loose or coherent fibrous material
  • C08J5/046—Reinforcing macromolecular compounds with loose or coherent fibrous material with synthetic macromolecular fibrous material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2260/00—Layered product comprising an impregnated, embedded, or bonded layer wherein the layer comprises an impregnation, embedding, or binder material
  • B32B2260/02—Composition of the impregnated, bonded or embedded layer
  • B32B2260/021—Fibrous or filamentary layer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2260/00—Layered product comprising an impregnated, embedded, or bonded layer wherein the layer comprises an impregnation, embedding, or binder material
  • B32B2260/04—Impregnation, embedding, or binder material
  • B32B2260/046—Synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
  • B32B2262/02—Synthetic macromolecular fibres
  • B32B2262/0261—Polyamide fibres
  • B32B2262/0269—Aromatic polyamide fibres
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2361/00—Characterised by the use of condensation polymers of aldehydes or ketones; Derivatives of such polymers
  • C08J2361/04—Condensation polymers of aldehydes or ketones with phenols only
  • C08J2361/06—Condensation polymers of aldehydes or ketones with phenols only of aldehydes with phenols
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2363/00—Characterised by the use of epoxy resins; Derivatives of epoxy resins
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S428/00—Stock material or miscellaneous articles
  • Y10S428/902—High modulus filament or fiber
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
  • Y10T428/24149—Honeycomb-like
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2933—Coated or with bond, impregnation or core
  • Y10T428/2964—Artificial fiber or filament
  • Y10T428/2967—Synthetic resin or polymer
  • Y10T428/2969—Polyamide, polyimide or polyester

Definitions

• Structures comprising a honeycomb core impregnated with a matrix resin wherein the core is a nonwoven paper of poly(m-phenylene isophthalamide) (MPD-I) fibrids and poly(p-phenylene terephthalamide) (PPD-T) fibers is taught 10 in Lin U.S. Patent 5,137,768.
• MPD-I poly(m-phenylene isophthalamide)
• PPD-T poly(p-phenylene terephthalamide)
• the honeycomb structure is prepared by cutting individual sheets from a roll of paper, applying stripes or node lines of adhesive to the sheets and laying the sheets together.
• the 15 adhesive is activated to bond the layers along the stripes.
• the expanded honeycomb structure is formed by pulling the sheets apart to the point where the adhesive prevents further separation. It is then dipped in epoxy or phenolic resin to impregnate the paper. Lin points out 20 that saturation of the paper by matrix resin is important to the honeycomb properties and for this reason, paper containing no more than 50 wt. percent of fibrid is employed. An excess of fibrids seals off the paper so that the striping adhesive does not adhere adequately. It 25 also prevents the matrix resin from penetrating sufficiently to develop the desired honeycomb properties. On the other hand, too little fibrid in the sheet results in a lack of adequate toughness.
• the present invention is a tough laminate with ⁇ good surface adhesion characteristics comprised of two outside layers and an inner layer, said inner layer constituting from 50 to 70 weight percent of the laminate and containing from about 60 to about 80 weight percent of poly(m-phenylene isophthalamide) fibrids with the remainder poly(m-phenylene isophthalamide) , poly(p- phenylene terephthalamide), copoly(p-phenylene/3,4 » - diphenyl ether terephthalamide, carbon, or glass floe, and with each outside layer constituting from 15 to 25 weight percent of the laminate and containing from about 60 to 70 weight percent of the floe with the remainder being poly(m-phenylene isophthalamide) fibrids, said layers having been calendered to form a coherent structure having a density of from 0.6 to 0.9 g/cc. Also encompassed is a honeycomb structure formed of the laminate and which has been impregnated with a resin.
• the laminated sheet of the present invention may be prepared by any of various methods.
• One method involves layering the paper on a papermaking machine to produce three distinct layers with predetermined fibrid/floc ratios in each layer followed by processing as normally done on a paper machine by pressing and drying. For example, blends of fibers and floe are fed to a 3- layer hydraulic type headbox which maintains separation of layers of ingredient until the slice exit where only limited mixing of the layers occurs.
• Another method is to ply three single sheets, each of selected fibrid/floc ratios and calendering.
• Still another procedure is to layer two layers on a papermaking machine (one outside layer and one-half of the core layer) and plying two of these papers in a calendering step. Additionally, one can conceive of various methods to deposit multiple layers on a forming wire and calendering.
• the laminated sheet have a basis weight of between l.l and 3.4 oz/yd 2 , and a density of from 0.6 to 0.9 g/cc after calendering, depending on thickness.
• the core layer or inner layer constitutes from 50 to 70% by weight of the laminated sheet structure of the present invention and contains about 60 to 80% by wt. of MPD-I fibrids with the remainder of said layer being floe.
• the core layer of the laminate is sandwiched between two outside layers, each constituting from 15 to 25% by weight of the laminate.
• the outside layers contain from about 60 to 70% by weight of floe with the remainder of said layers being MPD-I fibrids.
• MPD-I fibrids and floe may employ copolymers thereof containing up to 5 mol % of terephthaloyl units based on the mixture with isophthaloyl units.
• MPD-I is intended to include both the homopolymer and such copolymers.
• the construction of the laminate as shown in the Figure provides properties of particular value for honeycomb structures.
• the floc-rich outer layers (1) provide excellent substrates for the striping adhesive and for the impregnating epoxy or phenolic resin.
• the core layer (2) provides toughness and serves as a barrier to resin penetration while it does not readily absorb the adhesive or resin, it has no need to.
• each layer of the composite serves a separate function which in the aggregate provides a particularly useful core for honeycomb structure.
• the strength of the specimens is measured in an Instron Tester (Model 1122) using the following conditions:
• This example shows the preparation of a nonwoven sheet structure of the present invention using the poly(m- phenylene isophthalamide) fibrids and floe.
• Three separate handsheets must be produced and combined at the couch step to produce one layered paper sample.
• the outer ply handsheets containing the desired wt. % of the fibrids and desired wt. % of the floe were prepared from the calculated proportions of a 0.3% solids fibrid slurry and 0.25 inch floe.
• the handsheet was produced by putting the fibrids and floe and 2400 mis of water into a British Pulp Evaluation Apparatus (Mavis Engineering, Ltd. No. 8233) and dispersing them for 5 minutes.
• This stock was added to a Noble and Woods handsheet mold and additional water added.
• the stock solution was agitated 10 times with an agitator plate, then vacuum drained through a 100 mesh screen.
• the sample was couched between 2 plies (each side) of blotter paper to remove excess moisture.
• the handsheet was then transferred to blotter paper by slapping the sample and 100 mesh screen onto a table top.
• Another handsheet, to comprise the inner ply, containing the desired wt. % fibrids and desired wt. % floe was produced in a similar fashion.
• the sample was pressed on a hot press (Farrel Watson-Stillman, Model No. 9175-MR) at 1000 psi, 535 ⁇ F for 1 minute. Sample tensile properties and Surface Strength (SSTR) were measured and are reported below.
• the core layer of the control and Items A, B, C and D constitute 58%, 67%, 50%, 67% and 50% respectively of the laminate.
• the laminates A- D may be striped with adhesive and the sheets layed together.
• the adhesive is activated by heating and expanded into the honeycomb structure which can be impregnated with an epoxy or phenolic resin by dipping the core structure into the resin bath and curing as described in U.S. 5,137,768.
• the stock was prepared by putting the equivalent of 273 dry lbs of the fibrids with 638 equivalent dry lbs of 0.25 in. floe and 17,000 gallons of water in a tank, and dispersing it for 15 minutes. This stock was pumped to a standard inclined wire paper machine at a rate of 61.89 gallons per min./inch width to form a sheet of 9.28 lbs./3000 ft. ream at 150 feet per min. wire speed. This sheet was dried to a moisture level of -1%. This paper was used as the outer plies of the laminate.
• the inner ply was formed as taught in GROSS (U.S. 3,756,908) using similar fibrids and floe to those used above.
• the inner ply was 39.59 lbs./3000 ft. ream.
• the three plies were combined in calendering to form a single paper. Two samples of this paper were produced.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Laminated Bodies (AREA)
• Manufacturing Of Multi-Layer Textile Fabrics (AREA)
• Paper (AREA)

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• 1993
  • 1993-02-22 US US08/016,949 patent/US5320892A/en not_active Expired - Lifetime
• 1994
  • 1994-02-22 JP JP6519344A patent/JPH08507265A/ja active Pending
  • 1994-02-22 EP EP94909845A patent/EP0684905B1/de not_active Expired - Lifetime
  • 1994-02-22 WO PCT/US1994/002237 patent/WO1994019181A1/en active IP Right Grant
  • 1994-02-22 UA UA95083872A patent/UA29467C2/uk unknown
  • 1994-02-22 RU RU95121766A patent/RU2126327C1/ru not_active IP Right Cessation
  • 1994-02-22 DE DE69401344T patent/DE69401344T2/de not_active Expired - Fee Related

Non-Patent Citations (1)

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